Agilent Technologies InfinityLab LC Series User Manual page 185

12 Hardware Information
Interfaces
To provide maximum safety within a distributed analysis system, one line is
dedicated to SHUT DOWN the system's critical parts in case any module detects
a serious problem. To detect whether all participating modules are switched on
or properly powered, one line is defined to summarize the POWER ON state of all
connected modules. Control of analysis is maintained by signal readiness READY
for next analysis, followed by START of run and optional STOP of run triggered on
the respective lines. In addition PREPARE and START REQUEST may be issued.
The signal levels are defined as:
•
•
•
•
All common TTL circuits operate with a 5 V power supply. A TTL signal is defined
NOT E
as "low" or L when between 0 V and 0.8 V and "high" or H when between 2.0 V
and 5.0 V (with respect to the ground terminal).
Table 28
Pin
1
2
3
4
5
6
7
8
Agilent InfinityLab LC Series Multicolumn Thermostats User Manual
standard TTL levels (0 V is logic true, + 5.0 V is false),
fan-out is 10,
input load is 2.2 kOhm against + 5.0 V, and
output are open collector type, inputs/outputs (wired- or technique).
ERI signal distribution
Signal
START REQUEST
STOP
READY
POWER ON
SHUT DOWN
START
PREPARE
Description
(L) Request to start injection cycle (for example, by start key on any
module). Receiver is the autosampler.
(L) Request to reach system ready state as soon as possible (for
example, stop run, abort or finish and stop injection). Receiver is any
module performing run-time controlled activities.
(H) System is ready for next analysis. Receiver is any sequence con-
troller.
(H) All modules connected to system are switched on. Receiver is
any module relying on operation of others.
Not used
(L) System has serious problem (for example, leak: stops pump).
Receiver is any module capable to reduce safety risk.
(L) Request to start run / timetable. Receiver is any module perform-
ing run-time controlled activities.
(L) Request to prepare for analysis (for example, calibration, detec-
tor lamp on). Receiver is any module performing pre-analysis activi-
ties.
185